2968560

Appears in sequences

• E.g.f. (1-x)/(1-2x-3x^2+3x^3).at n=7A052664
• Number of periodic palindromes using exactly five different symbols.at n=17A056491
• The triangle T_2(n, m), where T_2(n, m) is the number of surjective multi-valued functions from {1, 1, 2, 3, ..., n-1} to {1, 2, 3, ..., m} by rows (n >= 1, 1 <= m <= n).at n=49A172106